Think about it this way - without a hermetic seal, equilibrium must eventually be achieved. Pressure and composition will therefore eventually be equalized. This happens through co2 exiting and o2 entering until that happens.

jaybeerman

This is a great thread. I'm going to start an "Aging beer" poll because I'm now curious what everyone else is doing. I'm not trying to steal the thunder from this thread and I agree that it's a great idea for an article.

Interesting that oxygen will try to permeate its way through the permeable seal of the bottle cap of a beer bottle that is of higher pressure. I am just really curious to how this works.

If the partial pressure of O2 in the Atm is greater than in the beer, the O2 will go in if the cap is permeable. Sierra Nevada changed from the twist offs to a pry off with a new O2 barrier cap liner to increase shelf life a few years back.

Logged

Jeff RankertAnn Arbor Brewers GuildAHA Governing Committee BJCP NationalHome-brewing, not just a hobby, it is a lifestyle!

Bottle caps are not impervious to o2, neither are carboys. Some oxidation still occurs. On top of that whatever oxidation that happened during transfer will also slowly change the beer.

However, if the pressure inside the bottled beer is greater than the surrounding pressure, then the bottle should not intake o2, rather it should diffuse CO2, and there should be no oxidation. Unless the brewer did not carbonate the bottles correctly, then I really can't see how air will try to force itself into a bottle that ideal has a higher pressure than its surroundings.

I'm not saying, I'm just saying.

Now, what the hell caused you to dig this old thread up? Even Jeff was still posting back then! Hope to see old Ben's face posting again here someday - that's for sure.

I know, it's counter-intuitive that the O2 will force it's way into the bottle and increase the pressure. But it does.

It is a case of gas/gas osmosis, and O2 can pass into the bottle because there is a higher percentage of O2 in the atmosphere than in the bottle, assuming the membrane is actually O2 permeable. It doesn't matter what the CO2 pressure is in the bottle, only what the relative O2 pressure is.

Bottle caps are not impervious to o2, neither are carboys. Some oxidation still occurs. On top of that whatever oxidation that happened during transfer will also slowly change the beer.

However, if the pressure inside the bottled beer is greater than the surrounding pressure, then the bottle should not intake o2, rather it should diffuse CO2, and there should be no oxidation. Unless the brewer did not carbonate the bottles correctly, then I really can't see how air will try to force itself into a bottle that ideal has a higher pressure than its surroundings.

I'm not saying, I'm just saying.

Now, what the hell caused you to dig this old thread up? Even Jeff was still posting back then! Hope to see old Ben's face posting again here someday - that's for sure.

Oh i don't know, I guess I was just diggin through my 2 yr old dopple bock stash, and this sounded interesting. Maybe if I submerged my aging beer in water then I wouldn't have to worry about oxidation when aging beer.

Logged

If you don't get in over your head, how are you ever going to know how tall you are.

I'm glad you dug it up! I thought it died too quickly anyways, and is a good topic. Aging under water - interesting idea! Course the caps tend to rust. And a doppelbock is one of those beer that does age very nicely!

Logged

jaybeerman

I'm glad you dug it up! I thought it died too quickly anyways, and is a good topic. Aging under water - interesting idea! Course the caps tend to rust. And a doppelbock is one of those beer that does age very nicely!

I know, it's counter-intuitive that the O2 will force it's way into the bottle and increase the pressure. But it does.

It is a case of gas/gas osmosis, and O2 can pass into the bottle because there is a higher percentage of O2 in the atmosphere than in the bottle, assuming the membrane is actually O2 permeable. It doesn't matter what the CO2 pressure is in the bottle, only what the relative O2 pressure is.

I'm glad you dug it up! I thought it died too quickly anyways, and is a good topic. Aging under water - interesting idea! Course the caps tend to rust. And a doppelbock is one of those beer that does age very nicely!

When aging brews under water I always use my titanium caps

I just have a room filled with CO2 and wear this outfit to go get beers . . .

I'm glad you dug it up! I thought it died too quickly anyways, and is a good topic. Aging under water - interesting idea! Course the caps tend to rust. And a doppelbock is one of those beer that does age very nicely!

When aging brews under water I always use my titanium caps

I just have a room filled with CO2 and wear this outfit to go get beers . . .

Now if only someone would invent a time machine kegerator.... just put your beer in and age it instantly. Not quite there? Just run it through again.

I'm glad you dug it up! I thought it died too quickly anyways, and is a good topic. Aging under water - interesting idea! Course the caps tend to rust. And a doppelbock is one of those beer that does age very nicely!

When aging brews under water I always use my titanium caps

I just have a room filled with CO2 and wear this outfit to go get beers . . .